Bird species diversity and nesting success in mature, clearcut and shelterwood forest in northern New Hampshire, USA

Bird species distribution and predation rates on natural and artificial nests were compared among unmanaged mature, shelterwood, and clearcut northern hardwoods forest to evaluate the effect of these practices on bird populations. Twenty-three of the 48 bird species detected during the study differed significantly in abundance among unmanaged mature forest, shelterwoods, and clearcuts. Results of multiple regressions of bird abundance and habitat variables suggest that differences in bird species distribution among treatments were the result of differences in habitat structure among treatments. Bird species diversity and species richness were significantly higher in shelterwoods than either mature forest or clearcuts, although there were bird species that occurred exclusively, or nearly so, in each of the three treatments. Predation rates on artificial nests were lowest in mature forest, and predation rates on natural nests was highest in mature forest, although neither of these differences was statistically significant. We conclude that use of partial cutting exclusively would result in the decline of several species of mature forest and clearcut specialists, and, consequently, a decrease in species diversity at the landscape scale. The use of a variety of silvicultural techniques is recommended to maintain bird species diversity in forested landscapes.